Future Humans

Image Credit / Nickolay Lamm

Image Credit / Nickolay Lamm

Humans evolved. We have been aware of this reality for 150 years, yet the implications are not apparent to most. What we have discovered about evolution is that it is A) not goal oriented and B) not hierarchical (i.e., there is no end state). This means that humans, as we currently exist, will not always exist.

Let me be clear before proceeding. This does not mean extinction is inevitable. But it does mean that our current form cannot persist indefinitely. We will change.

As a result of this knowledge, geneticist Dr. Alan Kwan and graphic designer Nickolay Lamm attempted to understand what we might look like in 20,000-100,000 years. Unfortunately for both individuals involved, their work is not science and should only be considered misleading science fiction.

Most biologists have a fantastic understanding of evolution (obviously). Biologists have revealed how the entire biosphere evolved. The theory of evolution by natural selection can explain in fantastic detail how a colony of the first replicating cells could diversify over time to produce endless forms most beautiful, including highly intelligent species like our own.

Despite the theory of evolution’s beautiful simplicity, clearly many people do not understand how it works at all. Evolution is a theory that can explain the history of organisms. Evolution can explain how things change. However, the theory is very rarely useful in predicting specific changes. From our knowledge of the history of biosphere, we can say some things about how a biosphere evolves, and therefore predict a few things about what we should suspect of the biosphere millions of years in the future. Evolutionary Biologist Richard Dawkins expounded on this quite well recently:

Evolution is very seldom in the business of predicting what is going to happen in a million years time. What I would say is that if you asked me what life is going to look like in say, ten million years or twenty million years, […] what there will be is a whole lot of different species doing pretty much the same thing as the present species are, but they’ll all be different. […] What you can predict is that there will be a similar range of species, doing a similar range of things, and that’s a fascinating thought.

Of course I agree with Dawkins main point, which is that we now understand how a biosphere is likely to change, even if we can’t say anything specifically about any one organism. We understand how a biosphere changes given the existence of certain traits like vision, hearing, echolocation, etc.

However, where I would perhaps disagree with Dawkins is that his analysis does not account for intelligence. Intelligence is here now. The Earth has a nervous system. Presently, that is our species: Homo sapiens. Intelligence is a game changer for evolution and it is a game changer for the biosphere. In the history of life on Earth, no intelligent species has ever created technology that itself evolves. As a result, we have no idea what the biosphere will look like over millions of years, given the presence of high intelligence. Anyone who tells you differently is lying.

This is fundamentally why the research done by Alan Kwan and Nickolay Lamm is wrong. But they are wrong for two other important reasons as well:

1) Conventional evolutionary mechanisms for change do not effect our species. For example, all species are subject to the law of natural selection. In all species that have ever existed most individuals did not survive long enough to reproduce. Differential non-random survival produced change over long spans of time. However humans are lifting themselves from natural selection because most people live long enough to reproduce. The mechanisms for change that will take natural selections place will be self-imposed through genetic engineering. This means that we will still be changing, but that change will literally be intelligent. Ironically, we will be intelligently designing ourselves. Although it is possible for me to posit this will occur, it is literally impossible for me to say what humans 500 or 1,000 years hence choose to change about their genetic makeup.

2) Technological evolution is speeding up, which is going to make biological evolution near irrelevant. All other species are subject to biological evolutionary processes that take tens of thousands of years (at least) to make considerable genomic changes. However, technological evolution (which is driven by culture) changes on yearly timescales. And that process is only getting faster. In the next 100 years we will likely witness more technological evolution than perhaps all of previous human history combined. How humans in only the next 100 years decide to fundamentally alter their form is debatable and realistically speaking, approaches unknowability. Many theories posit that the human form in 100 years will be primarily cyborg or robotic. It seems probable to me. But not 100% knowable.

Are we starting to see why predicting what we will look like in 100,000 years is ridiculous?

In the end, there is an important lesson to learn from the work of Dr. Kwan and Nickolay Lamm. First, it is important to acknowledge that the human form has not always appeared as it currently does. Second, that form will continue to change, and although we can gauge some type of directionality to that change, it is impossible to say what change will occur on the scales of deep time. Finally, we need to acknowledge that the human species is different than any life that has come before in the history of Earth. As I stated above, biologists have a good understanding of how life has evolved over the past 4 billion years. But we have no idea how life evolves given high intelligence. Therefore, we cannot predict what the biosphere will look like on the scales of deep time if we include the variable of intelligence. And we definitely can’t predict specific anatomical, physical, or genetic changes that may occur within our species.

Understanding human evolution is a science. We must make sure that when we discuss human evolution, both in the past and in contemporary times, that we focus on what is knowable. Attempting to understand what is probable in the next 100 years is in the realm of science. It is a maturing predictive science, but it is still science. In contrast, attempting to understand what will happen in the next 100,000 is impossible. It is science fiction.

What do you think about the future of human evolution?  Let Cadell know on Twitter!

Further Confirmation of the Big Bang

The Big Bang / BBC Science

The Big Bang / BBC Science

And it all started with a Big Bang…

Everyone knows our universe began with a Big Bang.  Actually, it is probably more accurate to say that approximately 13.8 billion years we know that what we can observe seemed to have underwent a significant phase transition, which directly led to the creation of all known matter and energy, and perhaps led to the existence of space and time itself.  But we don’t know that the Big Bang was the start of everything there is.  We don’t know whether there are other areas of our universe that existed pre-Big Bang.  And perhaps more importantly, we don’t know what caused the Big Bang itself.

However, I definitely don’t want to undersell how powerful a theory the Big Bang theory is.  The Big Bang theory is the central, guiding theory in all cosmology, and can explain nearly every aspect of the universe we observe.  That is quite an ambitious and successful theory by any measure.  And last month the Big Bang theory got a big boost by a team of international researchers that massively strengthened one of the four observational pillars of the Big Bang.

For everyone who doesn’t know, the four observational pillars of the Big Bang are:

  1. Expansion of the fabric of space
  2. Cosmic Background Radiation
  3. Abundance of light elements
  4. Galactic evolution and distribution

The observed expansion of spacetime itself is crucial to supporting the idea that our observed universe started with a Big Bang.  All galaxies are rushing apart from each other.  The further apart two galaxies are, the further apart they are rushing apart.  This expansion has been ongoing since the beginning of spacetime itself.  We can extrapolate expansion rates into the past, and with help from Einstein’s theory of general relativity, we can get an estimate on the conditions of the early universe.

The Cosmic Background Radiation (CBR) is equally important to understanding the Big Bang as the expansion of spacetime.  Discovered in the 1960s, the CBR is empirical confirmation that the universe was once in a primordial state with no galaxies or stars.  It is actually a snapshot of time approximately 380,000 years post-bang when the universe had just started to form atoms and photons were first able to roam freely.  This period in the universe’s development was predicted by the general theory of relativity, and thus is a fantastic example of the predictive power of the theory.

The fourth pillar (we’ll get to the third after!) is also important.  We now know that galaxies have evolved in a quite straightforward direction of time.  As the universe expanded gravity pulled slightly unevenly distributed matter into larger and larger clumps.  First gravity sculpted clouds of hydrogen.  Then young galaxies.  Then super clusters of galaxies.  Today the largest structures in the universe are galaxies connected like giant cosmic filaments.  Our universe as a giant web of matter (that is admittedly being ripped further and further apart).

Finally, the third pillar: the abundance of light elements.  For a while chemists wondered how we could possibly explain why 99% of the universe was composed of the lightest elements: hydrogen, helium, and lithium.  Stars are chemical factories, but the known process of thermonuclear fusion predicts that there should be a higher percentage of heavier elements than observed.  The only way we can explain the observed abundance of light elements is if the universe was once as hot and dense as a star for a short period of time.  If this was the case we should suspect that the universe in this state would have only been able to produce the lightest elements, which would explain why they are so abundant.

Wait… that is what the Big Bang theory predicts!  Perfect!  This phenomenon is called “Big Bang nucleosynthesis“.  But there is a problem.  Scientists have shown that the Big Bang theory roughly accounts for the amount of hydrogen and helium observed.  Over the past few decades astronomers have observed that there are two times the amount of two Lithium isotopes (Li-6 and Li-7) than Big Bang nucleosynthesis could account for.  This is a major problem that cosmologists have been working to resolve now for over twenty years.  Some scientists suspected that there could be pre-galactic fusion cores that we don’t have the technology to observe yet.  Some thought there was a big enough discrepancy in observations to that justify re-working the Big Bang theory itself.

However, last month the aforementioned Big Bang pillar-reinforcing study demonstrated that the problem was technological.  The authors claim that the observed over-abundance of lithium was due to poor observational quality in the past.  In their study, utilizing the powerful W.M. Keck Observatory’s 10-meter telescope, they completely reconciled the Big Bang theory with the observed abundance of lithium.

As a result, the pillars are stronger than ever.  Our universe, at least what we can observe of it, started with Big Bang.  Future studies related to reinforcing the pillar of the Big Bang will now be focused on observing the first stars and galaxies in our universe’s history.  In order to do that, astronomers will have to wait for the James Webb Space Telescope, which is the planned successor of Hubble and is scheduled to launch in 2018.

What do you think of this scientific development?  Let Cadell know on Twitter!

Into The Microscopic

Technology has allowed humanity to extend its vision to scales of reality that our ancestors could have never imagined. Ever more advanced telescopes are allowing us to see the birth pangs of the universe and the formation of the very first large scale objects. In contrast, ever more advanced microscopes are allowing us to see the very structure of all normal matter. It seems like scientists are in a race to see who can see further and deeper faster; and there may not be an “end” or “bottom” in either direction.

few days ago an epic milestone into new realities was reached when a team of physicists captured the first ever image of a hydrogen atom’s orbital structure. This was done using a quantum microscope, which should help physicists better understand the way atoms behave and interact.

Below is a ode to the microscopic. I have assembled images we have taken of objects at ever-decreasing size. The purpose of this exercise is to realize that at every scale of reality there is beauty and new wonder. Every scale of reality seems to be like a world unto itself, just like we imagine our “middle world” to be. Enjoy!

Largest known bacteria (0.001 m) (Image Credit / teachoceanscience.net)

Largest known bacteria (0.001 m) (Image Credit / teachoceanscience.net)

Human egg (0.0001 m) (Image Credit / thetimes.co.uk)

Human egg (0.0001 m) (Image Credit / thetimes.co.uk)

Cell nucleus (0.00001 m) (Image Credit / wikipedia.org)

Cell nucleus (0.00001 m) (Image Credit / wikipedia.org)

X Chromosome (0.000001 m) (Image Credit / scienceclarified.com)

X Chromosome (0.000001 m) (Image Credit / scienceclarified.com)

AIDS Virus (0.0000001 m) (Image Credit / science.nationalgeographic.com)

AIDS Virus (0.0000001 m) (Image Credit / science.nationalgeographic.com)

Hydrogen Atom's Electron Orbital (0.00000000001 m) (Image Credit / i09.com)

Hydrogen Atom’s Electron Orbital (0.00000000001 m) (Image Credit / i09.com)

Also, this is fun.

What do you think of the first picture of an electron orbital?  Let Cadell know on Twitter!

 

 

 

 

 

Fishing With Gorillas!

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Image Credit / GorillaDoctorsBlog.org

Gorilla culture and tool use is currently shrouded in relative mystery when compared to our understanding of other great apes.  For example, landmark behavioural studies detailing technological variation and distribution have been published for all great apes except gorillas (e.g., bonobos, chimpanzees, orangutans).

In the major gorilla tool use study I am aware of, gorillas were observed engaging in behaviours that can only reasonably be asserted to be technologically complex.  In one situation a gorilla was observed using a stick as a walking stick to aid in balance when crossing a river.  In another situation a gorilla was observed using shrubs to construct a bridge to cross a river.  Both of these observations demonstrate that gorillas have a very complex understanding of how physical systems work.  Furthermore, it is evidence that gorillas have a well-developed understanding of physical systems that extends beyond the acquisition of food.

In most situations throughout the animal kingdom, tool use is stimulated by an inaccessible and valuable nutritional resource.  This is true for New Caledonian crows, bearded capuchin monkeys, bottlenose dolphins, and most other tool using species.  Tool use that is directed towards non-food related goals is theorized to develop later.  So considering that gorillas have already been observed using tools for non-food related goals, it logically follows that they should have a tool kit that involves tools for procuring food.

Gorilla Doctors Blog is reporting that just such an observation has now been made.  The observation was made by Jean Felix, a medical doctor who was making a routine health check on a population of gorillas in Volcanoes National Park in Rwanda.

He reported that a second ranked silverback gorilla was:

eating ants by reaching his left hand into the ant pile before putting it in his mouth. He ran away at one point – it appeared the ants were biting his arm. Afterwards, juvenile female Lisanga joined him and used a piece of wood to retract the ants from their nest.

This is an interesting observation.  It seems as though a high ranking male was unaware that access to an ant food resource required a tool in order to prevent being attacked.  Considering that this was not an official primatological study, no further data is available that I’m aware of, but the observation raises several questions:

  • Was the juvenile female teaching the silverback?
  • Why was a younger individual aware of a tool that the older individual seemed unaware of?
  • Are female gorillas more adept tool users than males?

I don’t think any primatologists have the answers to these questions at present.  But, as I stated a few months ago, I am really excited to see what future research reveals about gorilla culture and tool use.

What do you think of this observation?  Let Cadell know on Twitter!

Infinite Boltzmann Brains

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I have finally encountered an idea that is too mind boggling for me to really comprehend. Unsurprisingly, it is from the world of theoretical physics. In a recent paper published in Physics Review D string theorists Claire Zukowski and Raphael Bousso explore the idea of Boltzmann brains.

Boltzmann brains are hypothesized self-aware (conscious) entities that are produced from random fluctuations in the fabric of spacetime. That just means that stochastic fluctuations in the level of entropy (disorder) in the universe could theoretically produce something complex (i.e., a self-aware entity) if given enough time. Apparently brains can theoretically blink into existence.

Physicist Ludwig Boltzmann first demonstrated that this was mathematically probable in the 19th century.

Fortunately for Boltzmann, dominant cosmological models today allow enough time for his brains. Current models suggest that our universe will produce Boltzmann brains post Black Hole Era, before the universe decays out of existence.

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Image Credit / Wikipedia

Boltzmann brains are a serious paradox for physicists to explain away. If there is enough time remaining in the life of the universe for essentially infinite number of Boltzmann brains to come into existence, our subjective experience of the universe will be highly unusual. We perceive the universe to have a directionality, or an “arrow of time” and all of our understanding of the physical laws derive from this observation. But if the experience of Boltzmann brains is the usual experience then we must question the universality of our physical theories. This is because in a post “Black Hole Era” universe there will be no distinguishable past and future; there will be no arrow of time.

Zukowski and Bousso are working to resolve this insane paradox. Zukowski stated:

It has to be more likely to be an ordinary observer than a Boltzmann brain

They believe that we have to rely on string theory to resolve the paradox. String theorists believe that our universe is just one of an infinite number of universes within a larger multiverse. In this multiverse, universes are constantly budding off of parent universes and inflating over time. Zukowski and Bousso contend that in this framework there are more universes with a discernible arrow of time than universes without (i.e., more universes decay before the appearance of Boltzmann brains than the opposite situation). This would mean experience like our own, with a discernible arrow of time, should be the dominant experience in the multiverse.

Obviously, this is all theoretical. The multiverse itself has not been empirically demonstrated, and is but one of several competing theories to describe the conditions that caused the big bang.

I suppose it is reassuring to know that if the multiverse does exist, it may not be overrun wit Boltzmann brains that have no concept of entropy?

As bizarre as this is to think about, it is too much for me to comprehend for evolutionary reasons. First, I have no idea how the trillions of atoms that create our conscious experience could possibly assemble randomly, even if given infinite time. Second, how strange would it be to have no concept of the arrow of time? To not have a temporal lineage with which to trace your own existence? You just exist, seemingly out of nowhere. You would have no baring on any direction at all. No possible way to understand your origin. A consciousness produced from nothing.

I’ll clarify that I am not saying the math is wrong. I am not qualified to say. Clearly if it is being taken seriously by physicists the math is something to be concerned about. And incredulity is not a good enough reason to doubt the possibility of such entities. If it is theoretically possible, so be it. I’m just saying it is an idea too bizarre for me to really grasp. I don’t think I’ve encountered a stranger idea.

Thanks physics.

What do you think of Boltzmann brains?  Let Cadell know on Twitter.

Cosmic Natural Selection

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If you regularly read this blog, you already know that I believe adaptive evolutionary processes explain system order in the universe. There does appear to be a unity between how systems evolve (whether they be chemical, biological, cultural, technological, etc.). In this sense, selection-like processes generate order in the natural world that many cultural groups assumed was intelligently designed. But can selection be extended to explain the universe itself?

Before humans knew that there were other planets in the universe, many people believed that Earth could only be explained by intelligent design (e.g., God). However, we now know that the Earth’s existence can be explained by probability. There are likely way more than sextillion planets in the observable universe, so it is not necessarily surprising that one suitable for complex life exists. In fact, it would not be surprising if billions of planets suitable for complex life existed just within our own galaxy.

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But people who make the God-of-the-gaps argument never really go away. Now that it is intellectually bankrupt to argue Earth (or life, or our star, or our solar system, or our galaxy) was intelligently designed, many turn to the universe itself. As physicists have pointed out, our universe is well-designed for the emergence of intelligent life (although not that well-designed).

Therefore, it is the job of 21st century science to uncover the mysteries as to why our universe appears to have the physical constants it does. At the moment, the theory is far ahead of the empirical evidence (unlike the situation in evolutionary biology). A dominant theory proposed to explain our universe’s physical constants is Cosmic Natural Selection (CNS). This theory, first explored by physicist Lee Smolin suggests that:

black holes may be mechanisms of universe reproduction within the multiverse, an extended cosmological environment in which universes grow, die, and reproduce. Rather than a “dead” singularity at the centre of blackholes, a point where energy and space go to extremely high densities, what occurs in Smolin’s theory is a “bounce” that produces a new universe with parameters stochastically different from the parent universe. Smolin theorizes that these descendant universes will be likely to have similar fundamental physical parameters to the parent universe (such as the fine structure constant, the proton to electron mass ratio, and others) but that these parameters, and perhaps to some degree the laws that derive from them, will be slightly altered in some stochastic fashion during the replication process. Each universe therefore potentially gives rise to as many new universes as it has black holes.

The analogy with how selection operates in biological systems is impossible to miss. Given that this is how complexity is generated by other natural systems, it seems logical that this could be the case of our universe (within the multiverse). In fact, a study published this month in the journal Complexityposits that Smolin’s CNS theory would mathematically be in concordance with the production of universe’s increasingly likely to produce black holes (and therefore universe’s conducive to complex life).

Let that sink in. If Smolin’s theory is true, our universe exists the way it does because of a cosmic natural selection between universe’s within a multiverse of universes with different physical laws.

But all theories need empirical evidence. There is currently no evidence for the existence of either a multiverse or successive generations of universes that transmit their fundamental constants. And it’s possible we won’t have that evidence in the near future (or ever).

Either way, I’m optimistic. Advances in physics theory are likely to further support the idea of a multiverse and the CNS. And I wouldn’t bet against CNS being lifted from theoretical obscurity. The idea has a certain Copernican principle to it. Just as scientific inquiry revealed that our planet, solar system, and galaxy were not particularly special, it seems increasingly likely that scientific inquiry will do the same for our universe as well.

What do you think of Cosmic Natural Selection?  Let Cadell know on Twitter!

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Should We Send Messages to Space

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Should we purposefully transmit messages to space? That is the question posed by a team of earth and space scientists in the February 2013 edition of Space Policy.

The question has been raised because various independent groups have been sending purposefully directed high-intensity messages intended for extraterrestrial intelligences (ETI), or METI’s.

The authors of this study made two conclusions regarding METI:

1) The benefits of radio communication on Earth today outweigh any benefits or harms that could arise from contact with ETI

2) Current METI efforts are weak, mostly symbolic, and harmless

But are the answers to independent groups sending messages into the cosmos really that simple? I mean I think it is fairly obvious that the potential for ETI in our galaxy should not deter our species from continuing to improve our communication abilities. We have no evidence to support the idea that there are intelligent civilizations in our galactic neighbourhood, much less evidence to support the idea that there is an ETI civilization that poses danger to our existence. However, expanding Earth’s radiosphere and directly sending messages into the cosmos are two very different things. For example, SETI astronomer Seth Shostak has claimed that, due to decreasing signal strength our radiosphere is not detectable beyond five light years. Whereas purposefully directed, high-intensity messages significantly increase Earth’s detectability beyond the radiosphere.

Essentially, this is the reason SETI pioneer Philip Morrison believed that we, “the newest children” in the cosmos, should be passive and just listen for a long time. We should not ‘shout at the cosmos’. We should not explicitly make our presence known before we know the types of intelligence that may exist.

This is a very complex issue. What should we do moving forward? Should we be engaged in an active search for ETI? Or should we be passive?

For me personally, I mostly agree with astrophysicist and science fiction author David Brin. He supports the International Academy of Astronautics Second Protocol for dealing with Transmissions from Planet Earth. This protocol states that:

all of those controlling radio telescopes forebear from significantly increasing Earth’s visibility with deliberate skyward emanations, until their plans were first discussed before open and widely accepted international fora.

To me, this seems like a reasonable position. If we are to purposefully send a METI, that message should be first discussed by an international panel of experts in astronomy, physics, biology, anthropology, history, and politics. And the message should be collectively sent as a message from Earth and by Earth; not from an independent collective. As David Brin stated, no one should feel free to:

broadcast from Earth, whatever, whenever, and however they want.

On the other hand, there are those who would prefer to completely ban METI’s; I disagree with that stance. Don’t get me wrong, I see wisdom in the perspective that we should remain silent, passively listening to the cosmos for thousands of years, before sending messages into a cosmic environment we are just beginning to understand. However, I feel as though we should send controlled and well thought out messages from our species and planet for two main reasons:

1) If there are highly advanced civilizations in the Milky Way, they would know we are here by studying the physical and chemical patterns of our planet, regardless of our radiosphere.

2) I believe it to be probable that any civilization with the capability of traveling to another solar system would not do so with the intention of eradicating life and high intelligence.

The first point is simple, not controversial, and easily explained: a sufficiently advanced civilization could easily detect the presence of our civilization by analyzing the spectrum of reflected ultraviolet, optical, and near-infrared sunlight for our planet’s surface. They could also, perhaps more easily, become cognizant of our existence from artificial nighttime lighting and the unusual chemical composition of our planet due to the excessive burning of fossil fuels.

The second point is far more complex, certainly controversial, and not easily explained. Biologists have often warned that contact between species that evolved in different ecosystems often leads to one species going extinct. Likewise, historians have argued that “first contact” between more advanced and less advanced civilizations have often led to disastrous inter-human relations (e.g., slavery, colonialism, civilization collapse, etc.). From this reasoning, they often conclude that if we make our presence known to a vastly more advanced civilization than our own, we are placing own existence in extreme peril.

However, consider the following: as our species has become more knowledgable and technologically advanced, we have also moved strongly in the direction of compassion, altruism, and the inclusion of all within the protection of law. I believe that this is directly tied to satiation. As we create a world of abundance; a world with drastically reduced levels of hunger and poverty, we elevate our cultural ideals. David Brin referred to this as:

an abstract sympathy, unleashed by full bellies and brains that are capable of seeing enlightened self interest in the long term survival of the world.

Natural selection is the driving force for the creation of our biosphere. It may be that natural selection is the driving force for all biological evolutionary processes in the universe. Natural selection permits populations to evolve via differential survival rates. And although we are a very young species, we are already close to releasing our species from this process. In essence, natural selection is permitted to operate because of resource scarcity. But as we continue to raise the standard of living for our speciesas a whole, we accelerate ourselves into a world where we all live long enough to reproduce. Differential survival rates will no longer drive our evolution. As a result, we also accelerate ourselves towards a world free of the byproducts of resource scarcity (i.e., extinction, war, slavery, etc).

When we create science fiction work depicting human-alien conflict, we are projecting biological system conflict produced from a world governed by natural selection. But the interaction between two highly advanced technologically-based systems will not likely be governed by that type of system conflict. A new, more intelligently directed form of evolutionary change should take the place of natural selection. Surely, any species with the capability of visiting our planet would have long ago released themselves from the biological tyranny of the process that created them.

As many scientists have pointed out, including theoretical physicist Paul Davies, biological intelligence is likely to be a fleeting phase in the evolution of the universe. If this is the case, it stands to reason that any civilization able to receive our messages and visit our planet would undoubtedly be post-biological. This essentially means they would be post-singularity. And a post-singularity species has not only lifted itself from a world governed by differential survival, but has also lifted itself from finite sentience and death. Therefore, I would not expect conflicts produced by the mechanism of natural selection to dominate an encounter between us and an advanced space faring civilization.

At least, that is my reasoning, and it is why I fully support a controlled, globally agreed upon form of METI. I think the benefits of discovering extraterrestrial intelligence and making “first contact” would outweigh the risks.

That being said, I am sure many would disagree with me. Perhaps it is foolish of me to assume that all advanced intelligent species would have lifted themselves from natural selection and tend towards extraterrestrial altruism. But that is why we must have open dialogue about METI. We can’t tolerate random independent groups to send messages without first consulting the global community. If we send messages we must be prudent. And, from my perspective, prudence would be making sure that any message is sent from Earth and by Earth. No one should be allowed to send whatever messages they want, whenever and however they want.

What do you think?  Let Cadell know on Twitter!

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The Ratchet Svbtle

The Largest Living Systems

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For anyone who studies evolution, it is important to realize that there are characteristic evolutionary patterns. For example, evolution tends towards greater complexity (although not always). Evolution also has a variable speed (which is often contingent on the environment). And a study recently published in PNAS indicates that evolutionary processes generally select for species-level living systems with universal size distribution. Science Daily summarized the importance of this universal size distribution well:

Flocks of birds, schools of fish, and groups of any other living organisms might have a mathematical function in common [… researchers] showed that for each species studied, body sizes were distributed according to the same mathematical expression, where the only unknown is the average size of the species in an ecosystem.

For the researchers of this study, these apparent universal size distribution may be useful for understanding how systems of living matter operate. However, this study made me think of the role of size in evolutionary processes. Specifically, what causes different living systems to evolve different sizes? And what living system has evolved the largest overall size?

The role of size in evolutionary processes has always been a contentious issue for evolutionary theorists. Central to the issue of size has been the idea that natural selection tends to drive the evolution of larger and larger overall size, regardless of whether the living system is a bacterium, a hydra, or a chimp. This observed trend has been labeled Cope’s rule after Edward Cope, a 19th century paleontologist who first proposed the trend. The late evolutionary theorist Stephen J. Gould disregarded Cope’s rule as a “psychological artifact”, however recent studies have provided empirical evidence to support the general pattern.

Paleontologist Joel Kingsolver supports the idea that evolution tends to favour large body size, stating that:

In 80 percent of the studies, there’s consistent selection favouring larger size.

Disappointingly, the theory to explain this pattern is still underdeveloped. In fact, Kingsolver contends that there may not be any universal driver of larger body size:

My guess is that it’s a mix of particular reasons for particular speices. You may be able to make through lean times better than someone who’s smaller. Females that are larger are able to produce more eggs. If males are competing for females, larger size is often favoured.

Paleontologist and science blogger Brian Switek echoed a similar perspective recently in an article about large dinosaur body size:

The evolutionary driving forces behind the evolution of truly huge body size are not clear, and likely differed from one group to the next.

Although evolutionary theory explaining the drive behind selection for larger body is underdeveloped, we do have a better idea of proximate determinants of body size. For example, many theorists have demonstrated that mode of locomotion and reproduction are both important factors either constraining or enabling large body size.

As Brian Switek discussed at length recently, the monstrous sauropod infraorder was able to “sidestep” the costs and risks that constrain mammalian size by “externalizing birth and development.” The size distribution of sauropods dwarfed the size distribution of all other known terrestrial organisms to ever exist.

So of these supermassive sauropods, what species holds the title of largest? The answer to this question was far more difficult to find than I originally thought. Michael Stevens from VSauce recently claimed that Giraffatitan was the largest known “with certainty of a complete skeleton”. Estimates of Giraffatitan come from one skeletal sample, and was thought to be 72-74 feet in length and weigh ~30-40 tons. Compare that to the largest known African elephant which weighed ~12 tons.

However, there is general consensus in the paleontological community that there were larger sauropods than Giraffatitan. Thankfully, I had some help from Brian Switek to better understand the contemporary debate:

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According to Switek Argentinosaurus and Supersaurus
are the leading contenders for heavyweights in the dinosaur world. The longest known of these giants was a Supersaurus that is estimated to be 108-111 feet long. The heaviest was a Argentinosaurus estimated to have weighed 73 tons. They were the giants of the gigantic sauropoda order.

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But we can’t forget about a living clade of animals that has experienced an explosive increase in size distribution: cetaceans. The largest (by far) of our mammalian cousins is the blue whale. And the blue whale is not just a contender for largest living animal, they are also contenders for largest animal of all time. In fact, in terms of absolute weight, it doesn’t appear to be close at all. Whereas Argentinosaurus weighed 73 tons, the largest known blue whale weighed over 200 tons! More than double the weight of the largest known dinosaur! But to be fair, blue whales don’t have to worry as much about the crushing weight of Earth’s gravity. The battle is much closer when we compare length: Supersaurus was between 108-111 feet and the largest known blue whale was ~110 feet.

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Blue whale Balaenoptera musculus = heaviest of all time?

The SV-POW paleontology blogger team made a brilliant point that we should suspect that Supersaurus was on average longer than blue whales because we are comparing with biased sample sizes:

A huge sample of blue whales included none longer than 110 feet, while our comparatively pathetic sample of sauropods has already turned in one animal (Supersaurus) that may have just edged that out, and another (A. fragillimus) that – assuming it was really as big as we think – blows it out of the water.

In case you were wondering, A. fragillimus is estimated to have been between 130-200 feet long! It completely blows my mind that a terrestrial organism can reach those sizes on our planet (just imagine how big they would have been if they had evolved on a planet the size of Mars!).

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The red image represents A. fragillimus, potentially the longest organism ever

In case you were wondering, no primate species has ever been a contender for largest living system. The primate order is comparatively small, with the largest contemporary species (gorillas) weighing between 300-400 lbs (or about 0.15-0.2 tons!). Even if we consider extinct species, no primate has ever even been a contender for largest land mammal. The largest, Gigantopithecus, weighed approximately 1,200 lbs (or about 0.6 tons). Of course, I think Gigantopithecus is aptly named (and I think sympatric populations of Homo erectus would agree); but they are only aptly named in comparison to our relatively puny order. Primate size has probably always been constrained by underdeveloped quadrupedalism and selection for long-term infant dependence.

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Reconstruction of Homo erectus and Gigantopithecus in Southeast Asia

However, it is interesting to know that all species body sizes (from prokaryotes to sauropods) are distributed according to a potentially universal power law. This universal describes how ecology influences average species size, while genetics contains variability around that average. In the future, I’ll be interested to see whether evolutionary theorists can better describe the adaptive pressures selecting for larger size. It is useful to have a grasp on the proximate causes of body size, but the ultimate causes will be necessary to better describe how living systems develop over time.

What do you think about the evolution of large size?  Let Cadell know on Twitter!

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“Earth-like”

Earth-Like Planets

The search for an Earth analogue is heating up. And although we may have to wait for the James Webb Space Telescope to see another Earth, indirect methods are bringing us closer and closer to finding an Earth-like exoplanet every month. These findings are also bringing us closer to estimating the number of Earth-like planets in the Milky Way (e.g., study 12).

The latest research, and for some the most exciting, was the discovery of Kepler-62e. Kepler-62e is a planet located approximately 1,200 light years away from Earth in the Kepler-62 star system. This system is composed of a smaller and cooler star than our Sun, and is accompanied by five known planets, two of which are rocky worlds in the stars habitable zone.

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From the limited data available to astronomers at this point in the detection process, Kepler-62e has been touted as the “most Earth-like” planet known to date. In fact, by utilizing the Earth Similarity Index (ESI) equation Kepler-62e scores a 0.82 (scale: 0-1.0). That score matches the unconfirmed exoplanet candidate Gliese 581 g (Figure 1).

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Figure 1 – Current Potential Habitable Exoplanets

ESI is calculated using data on the mean radius, bulk density, escape velocity, and surface temperature of an exoplanet. In the popular science media a high ESI (~0.80-1.00) is code for “Earth-sized planet within the habitable zone.” In essence that is what everyone means when they say “Earth-like.” But a growing number of scientists, myself included, are beginning to realize that we are getting way ahead of ourselves. At the moment we have no way of understanding an exoplanet’s geophysical history, present state, or the dynamics of the entire star system. Astronomer Phil Plait recently tempered enthusiasm re: Kepler-62e by stating there are too many unknowns to call it Earth-like yet:

Kepler-62e could have a thick CO2-laden blanket of air, making its surface temperature completely uninhabitable, like Venus. Or it might not. We just don’t know yet, and won’t for quite some time.

In short, more data on Kepler-62e could radically alter its ESI number from 0.82 to 0.44! And that is not even factoring in data on how a radically different solar system would affect Kepler-62e’s development and present state.

This frequent, and perhaps cavalier, use of the term “Earth-like” has caused some astronomers concern. Astrobiologist Caleb Scharf recently forced us to consider what is meant by “Earth-like” when used in the context of exoplanet discovery:

Utterance of [Earth-like] can evoke all sorts of images. It may make us think of oceans, beaches, mountains, deserts, forests, fluffy clouds, fluffy bunnies, warm summers, snowy winters, the local pub, or the fabulous hubbub of the local souk. But this is typically far from the meaning attached by scientists. It can simply indicate a planet with a rocky surface, rather than a world with a thick gaseous envelope. It can mean a world that is roughly the same mass and density as Earth. It can mean a planet orbiting a star like the Sun. Or it can just mean that we got bored of saying things like ‘a two-Earth mass object in a close to a circular orbit around a roughly 4 billion year old main-sequence star that is similar in mass to the Sun’.

For me, Scharf adequately articulates the complexity in this galactic search. He also reminds me that we still must be humbled by what we can’t know at this point in time. Our estimates on the number of Earth-like worlds are going to be in constant flux this century because our data will be imperfect. All we need to do is remind ourselves of Earth’s history to know our current data are insufficient to label an exoplanet “Earth-like”. Despite the fact that our planet’s orbit and size have been relatively static, it has gone through phases (and will go through future phases) that we would consider inhospitable.

On a final note, we must also remember that our planet has the current temperature, chemical composition, and general climate it does because of the biosphere. Life, as far as we know, creates an “Earth-like” world. So perhaps, moving forward, the term “Earth-like” should be reserved for planets that we can tell are operating in a Gaia-like way. By that I mean that we should only call a planet Earth-like if the light elements (e.g., carbon, nitrogen, sulphur, and nitrogen) are being dominated and controlled by biology.

What do you think about our search for another Earth?  Let Cadell know on Twitter!

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We Are Not Aquatic Apes

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Anthropology is a subject that has attracted its fair share of anti-intellectual theorists before. These anti-intellectuals are scientists from other areas of scientific inquiry that attempt to propose their own theories about who we are and where we came from despite having no formal anthropological training. Consequently, these people are usually a massive headache because they have no idea what they are talking about. Dr. Jonathan Marks did a great job elucidating why anthropology may attract this type of anti-intellectualism in a recent podcast I did with him.

Either way, I woke up yesterday to an infuriating article published in the Guardian: Big brains, no fur, sinuses… are these clues to our ancestors’ lives as ‘aquatic apes’? The article gave an international platform to several scientists that support the Aquatic Ape Hypothesis/Theory (AAH/T). This hypothesis proposes that there was a, as yet unidentified, aquatic phase of human evolution causing our ancestors to develop bipedalism, big brains, subcutaneous fat, sinuses, and lack of fur. Supporters of the AAH believe that these features are all indicative of an ancestral past spent living primarily in deep creeks, river banks, and the sea.

But there is one major problem: there is no evidence to support it. No evidence is usually a problem in science. No ancestral hominids have ever been found that lived in an aquatic environment.

The theory was first developed in 1960 by Sir Alister Hardy. Since then its supporters have generally been from biology. The AAH has received little to no serious consideration from the anthropological community. And nor should it. Paleontologist Chris Stringer accurately acknowledged in the Guardian article that:

[T]he whole aquatic ape package includes attributes that appeared at very different times in our evolution. If they were all the result of our lives in watery environments, we would have to have spent millions of years there and there is no evidence for this – not to mention crocodiles and other creatures would made the water a very dangerous place.

These are all very important points. If the AAH is valid we would have spent millions of years in a watery environment and we should suspect all features of the “aquatic ape package” to have evolved together, not at separate times. But this is not what paleoanthropology has taught us about our past. We know that our hominid ancestors lived primarily in woodlands 6 million years ago, and primarily in savanna landscapes 3 million years ago. Furthermore, two of the most important features that the AAH attempts to explain, bipedalism and encephalization, developed millions of years apart from each other.

Paleoanthropologist John Hawks has previously deconstructed why no anthropologists take the AAH seriously. He accurately pointed out that the AAH’s single assumption does not explain why we retained these “aquatic characteristics”:

Certainly it makes sense that hominids would develop new anatomies to adapt to such an alien [aquatic] environment. But once those hominids returned to land, forsaking their aquatic homeland, the same features that were adaptive in the water would now be maladaptive on land. What would prevent those hominids from reverting to the features of their land-based ancestors, as well as nearly every other medium-sized land mammal? More than simple phylogenetic inertia is required to explain this, since the very reasons that the aquatic ape theory rejects the savanna model would apply to the descendants of the aquatic apes when they moved to the savanna. […] It leaves the Aquatic Ape Theory explaining nothing whatsoever about the evolution of the hominids. This is why professional anthropologists reject the theory.

And yet anti-intellectuals still get a credible platform to spout nonsense about our aquatic past. Perhaps I could contain my disappointment if it all remained academic. However, ecologist Dr. Michael Crawford claims that our brain growth was solely because our aquatic ancestors had a diet rich in Docosahexaenoic acid (DHA), which is found in seafood. So he then makes the dangerous (and ridiculous) argument that:

[W]ithout a high DHA diet from seafood we could not have developed our big brains. We got smart from eating fish and living in water. More to the point, we now face a world in which sources of DHA – our fish stocks – are threatened. That has crucial consequences for our species. Without plentiful DHA, we face a future of increased mental illness and intellectual deterioration. We need to face up to that urgently. That is the real lesson of the aquatic ape theory.

Using an unsupported theory of human encephalization to claim that lack of fish in someone’s diet will lead to mental illness and intellectual deterioration is just anti-intellectual pseudoscience. Considering how far evolutionary theory has progressed in the past few decades, it is disappointing to see these scientists employ it so poorly. The Aquatic Ape Hypothesis is nothing more than an unsupported adaptive story. It has not been supported by evidence, and I find it highly unlikely that it ever will be.

In 2009, John Hawks thought the AAH fit the description of pseudoscience. In 2013, it still fits the description. We have never been aquatic apes.

What do you think of the AAH?  Let Cadell know on Twitter!

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